Conversion of carbonaceous materials



Patented Sept. l5, 1936 coNvEnsIoN or cAanoNA'cEoUs MATERIALS MathiasPier, Heidelberg, Bruno Engel, Mannheim, and Walter Kroenig,Ludwigshafen-onthe-Rhine, Germany, assignors to Standard` I. G. Company,Linden. N. J., a. corporation of- Delaware Application August is, 193e,semina. 685,229

In Germany August 26, 1932 2 Claims. (Cl. 196-53) The present inventionrelates to improvements in the treatmentwith hydrogenating gases ofcarbonaceous materials containing or giving rise to the formation ofasphalt to produce valuable' 5 hydrocarbon products and in particular toan advantageous manner of adding catalysts to the reagents.

The drawing represents in diagrammatic form an apparatus suitable forcarrying out the invention.

In the conversion by heat of carbonaceous materials comprising asphalt,i. e. containing or giving rise to the formation of asphalt, such ascoals vmade into' pastes with oils or oils containing asphalt, inparticular in the presence of hydrogenating gases, and more especiallyin the destructive hydrogenation of said materials, cata--4 lysts havehitherto been added thereto before their entry into the apparatus, themixture then being brought to the reaction temperature in a preheater.In this process it was observed that during the heating the highmolecular asphaltlike constituents of the initial materials penetrateinto the pores of the catalyst and thus impair its activity already atthe beginning of the reaction. Furthermore the small particles ofcatalyst become stuck together by the asphalt forming larger particles,which then settle inan undesirable manner. The catalysis thereby suffersowing to the resulting absence in the reaction space of active catalystdue to the setting of large amounts of stuck catalyst which is thereforewasted. The said conglomeration of catalyst may in some .cases even takeplace when a suspension prepared by grinding the catalyst with an oilcontaining asphalt is allowed to stand for some time while hot.

We have now found that the disadvantages hereinbefore mentioned areavoided by dispers- 40 ing the catalyst in the absence of asphalt in anoil which is freefrom asphalt and which when mixed with the carbonaceousmaterial to be treated. or the vproducts lformed. therefrom does notcause fiocculation of the asphalt present or formed during the workingup and then adding the suspension to the initial material to be treatedor undergoing treatment. The term "dispersing" includes suspending ormaking up into a paste. By the expression "oils not causing flocculationof asphalt we mean either oils which do not cause fiocculation even whenadded in large quantities or oils employed in such amounts as do notcause fiocculation though larger amounts thereof are capable of causingfiocculation. Thus for .example also a middle or heavy oil consisting of5 'a large proportion of saturated hydrocarbons may be employed if it isadded in but, so small quantities that no iiocculation takes place. Byasphalts we understand substances which are chemically similar tonatural asphalt and which 10 represent black brown, solidor vsemi-solidhigh molecular hydrocarbon compounds containing oxygen and in most casesalso sulphur, which are dissolved or suspended in mineral oils or otherliquid hydrocarbon products such as prod- 15 ucts obtained by thedestructive hydrogenation of carbonaceous materials and which may inpart be precipitated from the said liquid hydrocarbon products4 bybenzine and in part from their. solution in ether by addition of alcohol(see Holde 20 Kohlenwasserstoffl'e und Fette, 1933, page 164) Thepresent invention is of particular advantage in processes in which thecatalyst dispersion in oil is admixed with the initial materials priorto any heating or preheating necessary to bring 25 them to the reactiontemperature. The said heating is preferably carried out with an additionof a hydrogenating gas such as hydrogen.

By stating that the dispersion o! the catalyst in an-oil free fromasphalt should take place in $0 the absence of asphalt we wish` toexclude a treatment in which the catalyst is flrst contacted with anasphalt-containing oil and then further distributed in another oil whichmay be free from asphalt; since this procedure would result in thepreparation of a catalyst which is soon clogged up with asphalte. Thepre-treatment of the catalyst in the absence of asphalt with an oil freefrom asphalt has the result that the capacity of the catalyst foradsorption is practically com- 40 pletely used up by the oil free fromasphalt, so that the catalyst, for'example during its heating uptogether with the initial materialfhas practically no adsorptivecapacity for the asphaltic constituents, although the invention is notlimited by this 45 theory. It is preferable to add the suspension of thecatalyst in the oil free from asphalt to the oil containing asphaltVwhich is to be worked up, at a time which is not too long before theworking up, because when the mixture is allowed to stand 6e fora verylong period of time an exchange between the oil free from asphalt on thesurface of the catalyst and the oil containing asphalt commences to takeplace.

For the purposes of the present invention an oil is considered to befree from asphalt, if it is entirely or practically free therefrom thatis to say, if it does not contain asphalt in amounts above 0.5 per centand preferably not above 0.3 per cent by Weight. The amount of asphaltcontained in the oil as dened in the present specification is determinedas follows: 2 grams of oil are mixed with 5 cubic centimeters of benzeneand 100 cubic centimeters of normal benzine, and allowed to stand for 12hours. The asphalt which precipitates'y out is lfiltered oi, washed onthe lter with normal benzine and dissolved in benzene. The benzene isevaporated oir, and the residual asphalt is dried and weighed. As oilsfree from asphalt may be mentioned middle oils or heavy ollsanswering tosaid specication and it is particularly advantageous to employ a heavyoil answering to said specicationsv obtained by destructivehydrogenation from the initial materials to be worked up. Thus middleoils 0r heavy oils obtained by the destructive hydrogenation of mineralcoals or mineral coal tars are of advantage as oils free from asphaltsto be pasted up with the nely divided. catalysts. Also frac tions ofthese tars themselves are suitable for this purpose. `As furtherexamples of such oils may be mentioned anthracene oil free from asphaltor oils, preferably of middle oil boiling point range,

obtained by the destructive hydrogenation of carbonaceous materials attemperatures of the upper half of the temperature range suitable forthis reaction, whereby a high content oi' aromatic hydrocarbons isimparted to the final products. Also naphthenic or paraiiinic base oilscome into question, the latter being employed in such smallV quantitiesthat no flocculation takes place. It is of advantage to select an oil asdispersing medium which has a gravity of the order of the catalyst to bedispersed or previously to intimately mix the 2 catalyst to be dispersedin theoil with a solid vsubstance which adapts the gravity of the solidmixture to that of the oil in which it is to be dispersed.

v'Ihese oils, when not added in restricted amounts, should notcontain somuch aliphaticconstituents rich in hydrogen that there is any dangerwhen mixing these v'oils with an asphalt containing oil that afiocculation of the asphalt which would lead to clogging of theapparatus, occurs. As a rule not more than 20 per cent, preferably lessthan l5 per cent, of aliphatic constituents rich in hydrogen reckoned onthe initial material comprising asphalt should be added to the latter.

'Ihe invention is of particular importance for working up tars ormineral oils containing asphalt,

ly treated in accordance with the present invenf tion.

As catalysts may be mentioned those having a hydrogenation action,especially metals, or their compounds, of the 2nd tothe 8th group of theperiodic system, as foriexample zinc, magnesium,

cadmium, boron, titanium, tin, lead, vanadium,

manganese, i'ron, cobalt, rhenium and especially those of the 6th group,such as chromium, molybdenum, tungsten 'and uranium. Advantageous ycompounds are oxides and sulphides. The catachloride dissolved innaphthenic acidvor oleic acid,

may be employed. The catalytic material may l also be brought on to thecarrier substance while it is in a colloidal state oi' dispersion.

The expression treatment by heat, preferably with hydrogenating gaseswhere herein employed is intended to comprise the most variousreactions. The said treatment may be used to produce hydrocarbons of allsorts by cracking or by. destructive hydrogenation, such as motor fuels,middle oils, kerosene and lubricating oils. The said expression alsoincludes the removal of nonhydrocarbon impurities, n such as sulphuroroxygen-containing substances or nitrogen compounds by the action ofhydrogen or gases containing or supplying hydrogen from crudecarbonaceous materials containing or giving rise to asphalt, for examplethe refining by treatment with hydrogen of crude goenzolcontainingasphalt, of crude motor fuels or of lubricating oils, containing orgiving rise to asphalt. 'I'he said expression further includes theconversion of oxygen or sulphur containing organic compounds containingor giving rise to asphalts to produce the corresponding hydrocarbons orhydrogenated hydrocarbons, for example the conversion of phenols orcresols containing asphaltic substances into the correasphalt and moreparticularly of unsaturated hydrocarbons of said'nature or of aromaticcompounds containing asphalt and more particularly of aromatichydrocarbons of said nature, for example, to produce hydroaromatichydrocarbons.

'I'he said reactions by heat treatment, especially with hydrogen orhydrogen containing gases, are effected in the liquid phase and usuallycarried out at temperatures between 250 and 700 C., usually between 300and 700 C. and more preferably between 380 and 550 C.l The pressuresemployed may be atmospheric or superatmospheric; they are preferably inexcess of 20 atmospheres and more advantageously in excess of 50atmospheres. n some reactions, however,

' for example, in the reiining of crude benzol containing asphalt,rather low pressures, for example, of the order of 40 atmospheres may beemployed. Generally, however, pressures of about 100, 200, 300, 500 andin some cases even 1000 atmospheres come into question.

'I'he amount of hydrogen maintained in the reaction space and partsconnected therewith, ii' any, varies greatly with the nature of theparticular initial materials treated or according to the result in view.In general 400, 600, 1000 cubic meters or more of hydrogen, measuredunder normal conditions of temperature and pressure, per

ton ofcarbonaceous material treated may be used. It is particularlyadvantageous to operate by continuously introducing fresh carbonaceousinaterial into the reaction vessel and to continuously remove productsItherefrom. If desired several reaction vessels may be employed in whichdifferent conditions of temperature and/or pressure may, if necessary,be maintained and in which different catalysts may also be employed.Sulciently converted reaction products may be removed behind any of thereaction vessels. Mai terials which have not been suiilciently reactedon may be recycled or treated in a further reaction vessel. Thesubsequent stages may, if desiredkbe carried out in the gaseous phase,for example to produce anti-knock motor fuels. One of the subsequentstages may also take the form of a cracking. I

Referring to the drawing, numeral I indicates a. -tank in which acatalyst is'produced-either in solution or in suspended form, as seemsdesirable. Line 2 conducts this solution or suspension into a mixingchamber 3- into which a carrier material may be placed. The mixingdevice is fitted with a stirring mechanism and air is injected by meansof a line 5 into the catalyst in order to spray the solution orsuspension over the carrier material. e

The mixing device is also fitted with a chute 6 for discharging ,thecatalyst after it has been produced in a dry form into a mixingchamber 1. Asphalt free oil of the types mentioned above, such asanthracene oil, is fed into th mixing chamber from aA storage vessel 0aand this mixture is then passed into a disintegrator AA pump 9 may beutilized to pass the material discharged from the disintegrator back tothe mixing chamber by pipe I0 in order to gain uniformity and a portionthereof may be drawn oil by a vpipe II and discharged into a secondmixing chamber I2 which is also tted with a stirrer I3 and into which amain body4 of the oil to be subjected to the hydrogenating treatment isconducted by aline I4 from storage I5. The admixture of the threeingredients, namely the catalyst, the asphalt free oil and the oil to betreated, is then passed by a line I0 and pump I1 to a preheater I8.Hydrogen is introduced preferably into the inlet of the preheater bymeans of a pipe I9 and the preheated mixture is passed into a reaction'chamber 20. The reaction products may be withdrawn from the top of thereaction chamber by a line 2I and discharged into a separating vessel22. Liquid and solid materials can be withdrawn by pipe 23 while thevapors pass overhead by a pipe 24 to a condenser 25 and a separatingvessel 26 from which gases are removed by 21 and the liquefied productby 28.

CThe expression hydrogenating gases" means, where herein employed,hydrogen alone or gases containing or supplying hydrogen, for example amixture of hydrogen with nitrogen, or water gas,

Advantageously so much of the 4Vcatalyst dispersion is admixed lwith thecarbonaceous material that the nal mixture'contains between 0.05

and 5 per cent by weight and preferably between not restricted to theseexamples.

Example 1 Brown coal small coke which has been activated with steam at900 C. is impregnated with an ammoniacal solution of molybdic acidsothat the coke contains 2 per cent bf molybdic acid. The catalyst thusprepared is then ground to colloidal fineness in a percussion cross milland mixed with such an amount of-a heavy oil free from asphalt (obtainedas hereinafter described) that a suspension containing 30 percentvofcatalyst isyobtained. This mixture of oil and catalyst has added theretoa German petroleum boiling above 325 C. and containing asphaltl so thatthe latter contains 1 per cent of catalyst. The mixture is thenheated'to 475 C. with hydrogen under a pressure of 200 atmospheresandrled throug a reaction vessel; 1650 cubic meters of hydroge are usedfor each metric ton of oil.A The pro ucts leaving the reaction vesselare led into a separating vessel kept` at 460 C. in which a liquid levelis maintained.' From the bottom of the vessel are withdrawn 6 per cent(calculated with reference to the treated material) of high boilingproducts containing catalyst, while the remainder of the reactionproducts together with the hydrogen are suppliedto a fractionatingcoiumn. From this column aire obtainedA 55 per cent of constituentsboiling up to 325 C., which conv sist of 27 per cent of benzine and 73per cent of middle oil, and 45 per centof constituents boiling above 325C. which are free from asphalt. A part of the latter are employed, asalready mentioned, for mixing with the catalyst. The remainder may besupplied to the same or another reaction vessel for further conversioninto constituents of lower boiling point.

If the catalyst is directly added to the asphaltic initial oil to beconverted the catalyst particles become soon stuck together and thecatalyst deposits in substantial 'quantities in the preheater and in thereaction vessel, whereby inconveniences such as a decrease in theactivity of the catalyst, a decrease of the volume of the reaction spaceand a clogging up of the preheating coils are encountered after sometime oi operation.

Example 2 Active carbon is impregnated with 5 per cent of zinc chlorideand then mixed with a'lubricating oil, f ree from asphalt, obtained froma German mineral cil by distillation or by destructive hydrogenation insuch an amount that a suspension containing 30 per cent of catalyst isformed. This suspension is thereupon added to an oil fraction containingasphalt and boiling above 325 C. which is obtained from a German mineraloil, in such an amount that the mixture contains 1 per cent of catalyst.This mixture is then heated in a heating tubey system under a pressureof 50 atmospheres to 485 C. and subsequently passed through a crackingspace connected with said tube system and having a greater diameter thanthe tubes of this system. In this manner benzine is obtained in a yieldof 42.8 per cent with reference to the initial asphalt containing oil.'If the catalyst is directly added to this oil the inconveniencesdescribed in Example 1 are encountered.

What we claim iszl 1. In a process of destructive hydrogenation ofcarbonaceous materials rich in asphalts or substances which produceasphalt during the treatment, the steps of first dispersing a nelydivided catalytic material in an oil free from asphalt and which whenmixed with the carbonaceous material to be treated or the product formedtherefrom does not cause flocculation'of asphalt iniaoume Y tiallypresent or formed during the process to form a paste containing 10 to60% of catalyst, adding the suspension thus formed to the carbonaceousmaterial to be treated, to form a mixture containing from .05 to 5% ofcatalyst, and then subjecting the mixture to destructive hydrogenation.

2. Process according to claim '1 in which the proportion o! the catalystis` .1 to 1.5% ofthe oil mixture.

MATHIAS PIER. BRUNO ENGEL. WALTER KROENIG.

